Robert abbott hadfield



FIE ND A. G. McK. JACK.

UF 0' OF STEEL INGOTS.

P C TION FILED JULY 14. I917.

Patented Dec. 2, 1919.

M a 2 v .a 0 m nmm Z y wm flmw MW. 34 m pivirnn s rarns Parana, opinion ROBERTABBOTT HAD-FIELD, OF WESTMINSTER, AND ALEXANDER GEORGE MCKENZIE {ACK, 0]? SHEFFIELD, ENGLAND.

MANUFACTURE'OF STEEL INGOTS.

To all whom it may concern:

Be it known that we, Sir ROBERT Annot 'r I'IADFIELD, baronet,F. R. S., and ALEXANDER Gnonon MCKENZIE JAcK, subjects of the King of Great Britain and Ireland, residing, respectively, at \Vestminster, England, and Shefiield, in the county of York, England, have invented Improvements in or Relating to the Manufacture of Steel Ingots, of which the following is'a specification.

In the manufacture of ingots of steel or other extrusable metal, and especially of such ingots which are to be subjected to the process of extrusion, it has heretofore been usual to cast steel and other ingots of taper shape in order that they may more readily be removed from their molds, the smaller ends being either at the top or at the bottom. When however such a taper ingot is placed in a matrix arranged in either a vertical or a horizontal position, and especially the latter, preparatory to being subjected to an extrusion process, as for example for producing hollow, articles therefrom, .the small end of the ingot, owing to its having no centering means, may not be arrang d centrally within the matrix but is usuallynearer to one side of the die thanthe other, and, in the case of a matrix arranged horizontally, rests on the lower side in the matrix, with the result that upon forcing an extruding bar or plunger vertically or hori- Zontally into the ingot, the hole thus formed in the latter is not disposed centrally throughout the ingot but on the contrary is generally eccentric thereto except at the end first formed by the bar or plunger so that the metal I is not disposed symmetrically around the hole throughout its entire length.

N ow the present invention has for object to obviate the disadvantage above referred to and while producing aningot of gradually decreasing cross sectional area along its length, so as in effect to be of taper shape, to yet provide a gradually increasing cooling surface, preferably from top tobottom, to insure the proper cooling of the ingot after being cast, as well as means for centering the ingot in an extrusion die.

Specification of Letters Patent. r Pwbgntedl Dec. 2, 19198).

Application filed July 14, 1917. Serial No. 180,603. 7

course suitably shaped internally, to cause this formation to beimparted to the ingots. Ingots according to the invention may be circular, square, rectangular or polygonal in general or overall shape as seen in end view or plan, as may be desiiredfand in the case of an ingot which is circular in section at its upper end the grooves or flutes may be somewhat closely pitched so that in a steel ingot of ordinary size, say of about twelve inches in diameter or width, there will be several grooves or flutes, say for example siX to twelve. 1

In 'the accompanying illustrative drawings Figure 1 is a side elevation and Fig. 2 an end View of the base, of a grooved or fluted steel ingot constructed according to the invention, the upper end portion ofthe .ingot being circular in section. Figs. 3, ,4,

5, 6, 7 and 8 are cross sections on the lines A A, B B, C C, D D, E E and F F respectively of Fig. 1. Figs. 9 and 10 are similar views to'Figs; 1 and 2 respectively, and Fig. 11 a cross section on the line G G of Fig. 9 showing a grooved or fluted steel ingot of hexagonal shape while Fig. 12 shows in plan view, an ingot of square shape.

In the example shown in Figs. 1 to 8 inclusive, the ingot is circular in general or overall shape as seen in plan, a, being the grooves or flutes of concave shape in cross section extending from an upper cylindri cal portion 6 to the bottom. of the ingot. c is the ordinary discard portion or feeding head of the ingot which is cut oil before .the ingot is converted into the desired arti cle by extrusion or otherwise. The diameter of the ingot'is slightly greater at the portion Z than at the base to facilitate withdrawal from the casting mold, and the grooves or flutes a are of gradually increas ing depth in an inward or transverse direction from their upper to their lower ends,

a after 5 substantially parallel, to the longitudinal axis of the ingot.

In Figs. 9, l0 and 11 the ingot is of polygonal shapethroughout its length, being shown as of hexagonal shape,-each side being grooved or fluted as described.

In Fig. 12 the ingot is square at the top except thatthe corners are rounded, the contiguous grooves or flutes gradually getting deeper in the transverse direction as they proceed toward the lower end of the ingot as in the other examples.

In each case the measurements across the outer rounded edges of the ribs d are the same, or practically so, from end to end of the ingot, except for the slight extent required to facilitate *removal of the ingot from its casting mold as indicated above,

- that is to say, the measurements are substantially the same.

Thelower end of the-ingot may be of rounded shape as shown in Fig. 1, or of flat shape asshown in Fig. .9. For some pur-,

poses it is preferably made of rounded shape. 4

By constructlng ingots in the manner dean ingot the sectional area of which is greatest at its upper end, as in the example shown in Figs. 1 to 8 inclusive, which is the face ofthe ingot will be of gradually increasing" area in a downward direction whereas the cross sectional area ofthe ingot will be gradually decreasing from or near the top to the bottom of the ingot so that eing cast, the ingot will cool most rapidly at the bottom, not only by reason of the greater cooling surface, but also by reason of theconductionaway of heat due Wit'h. the mold and to'tlie flutes generally, the rate of cooling decreasing upwardly as in an ingot which is cast with its largest sectionat its upper end. By this means, as the molten metal gradually cools and solidifies from the lower end' of the ingot upward, the molten metal above is able to descend and compensatefor contraction on cooling and prevent piping throughout the entire length .of the ingot so that the whole of the ingot, after removal of the discard portion 0 is available foruse.

ingot will be disposed symmetrically and scribed, it 'will be seen that in the case of.

form preferred, the external cooling sun;

to the edges of the ribs at being in contact Furthermore, such I an ngot when placed 1n a'matrlx, preparaconcentrically around such hole and all parts of its sectional areaw1ll have been sub-' jected substantially to the same pressure, the flutes or grooves being gradually. and equally filled up or eliminated by expansion as the metal is extruded.

It will be observed that the uniform arrangement of-the numerous grooves and the comparatively narrow intervening ribs enables the ingot to be used with marked "effect in carrying out the extrusion method in which the ingot is first punched, centrally and then subjected to the action of,mandrels or asuccession of mandrels to produce, for example, gun-tubes, howitzers, etc. The longitudinal grooves are of substantially uniform width from end to end but of vary ing depth and they constitute arcs of closely approximated intersecting circles. ample, in Fig. 3 the circles indicated by the arcs would be approximated; in Fig. 4 the circles would touch each other; while in the succeeding figures the circles would intersect; and so on until finally theywould merge in Fig. 8. The ribs are, of course, comparatively narrow until they finally disappear in Fig. 8 in the plain-cylindrical part b of the ingot. These intervening ribs have substantially the same circumference as the cylindrical part, b, and gradually decrease in width from one end to the other of the ingot. This uniform treatment of the surface by the formation of the concave grooves illustrated and described secures the best results when using the ingot to form a gun tube, for example. The metal under radial pressure fillsout the concave grooves until the whole tube is substantially ofthe same formation from end to end and of substantially the same density, the effect of the radial pressure being progressively greater as it proceeds from the top 'to'the bottom of the ingot.

In the form illustrated in Figs. 1-11 the gun tube is substantially completed by the action of the mandrels alone upon the ingot thus grooved. .Therefore by the described uniform relation of the grooves a great economy is secured, especially when the ingot is used for the formation of gun tubes,'howitzers, etc. Y

For the purpose of insuring complete concentricity of the extruded ingot,.the measurement of the ingot across the ribs may brslightly in excess of the internal diameter of i the extruding die so that the ingot may rcqulre to be sub e'cted to a slight end pressure 1n order to bring it into position in the matrix for extrusion.

For ex-,

trio with a matrix for a forging operation.

With reference to the grooves it may be stated in illustrative terms that-they gradually fade away toward one end of the ingot.

In mathematioal'terms it may be said that the cross sectional area and the perimeter of that area vary between the limits and I .2 n(21rr) where n represents any value greater than 1. i

What we claim is I 1. A metal ingot, having a longitudinally grooved surface formed by grooves of varying transverse depth along their length, the outer edges of the ribs between the grooves being substantially parallel to the axis of the ingot.-

2. A metal ingot having in its peripheral surface longitudinal grooves of varying depth along their length with the outer edges of the ribs between the grooves of convex shape and substantially parallel to the longitudinal axis of the ingot.

3. A metal ingot of substntially uniform overall dimensions along its length and having a longitudinally groovedperipheral surface, the grooves being of varying transverse. depth along their length and of concave shape in cross section.

4. A metal ingot of substantially uniform overall dimensions along its length and having longitudinal peripheral grooves of concave/shapeand of varying transverse depth 40 along their "length, .theribs between such grooves having rounded edges.

A metal ingot of tapering-cross sec-' tional area, having in its peripheral sur-:

face longitudinal grooves of concave shape 'Twith the edges of the. ribs between the grooves substantially .parallel to, the axis of the ingot.

.6. Av metal ingot having a rounded lower longitudinal axis of the ingot.

end and longitudinal grooves of varying transverse depth along their length and extendlngfrom its-lower end portion upward,

the transverse depth being greatest 'at the lower ends of the grooves and the edges of the ribs between the grooves being substan tially parallel to the axis of the ingot.

7. Aimetalingot provided for part of its,

length with longitudinal grooves of varying transverse depth from their lower ends upward, the edges of the ribs between the axis of the ingot. 4

8. A metal ingot providedfor part of its le'ngthjwith longitudinal grooves of concave section and of graduallyklecreasing transgrooves being substantially parallel to the verse depth from their lower ends upward, 5 the; remaining portion of the ingot being of substantially uniform cross section and the ribs between the grooves. having their edges substantially parallel to the axis of the ingot and flush with theungroovedportion of the ingot.

end portion, the intermediate portion being formedwith longitudinal grooves ofcon- 5 cave section and of gradually decreasing transverse depth from their lower ends upward and the ribs between the grooves having rounded outer edges substantially parallel to the axis of the ingot and flush'90 with the surface of the cylindrical'portion of the ingot.

11. A metal ingot having a portion of its longitudinal surface of cylindrical shape and the ren'iainder and greater portion of its length of longitudinally grooved shape, the latter portion being of waved shape circumferentially withthe concave grooves of greater width than the intermediate ribs' or ridges and of varying transverse depth along their length, the ribs or ridges having their peripheral edges or surfaces substantially parallel to the axis of the ridge.

12. A metal ingot havin a polyhedral longitudinally grooved surface formedof alternating longitudinally extending grooves of concave shape in cross section and inter- 'vening ribs of convex shape incross section, the grooves being of varying transverse depth along their length and of greater Width than the ribs, and the outer edges of the ribs being substantially parallel to the 13. A metal ingot having a longitudinally grooved surface formed by grooves of varying transverse depth along their length, the outer edges of the narrow ribs between the grooves being substantially parallel to the longitudinal axisof the ingot andtlie ribs so formed being substantially, triangular in 15. Acast pyramidalingot having means for maintaining its longitudinal axis concentric with a matrix for a forging operation.

16. A cast ingot wherein the relation between thecross-section area and the perimeter of that area vary betwen the limits substantially uniform width from end to end but of varying depth,

19. A metal ingot adapted to fit the bore of amatrix and having longitudinal grooves of varying width from end to end forming ingot having longitudinal a major part of its surface with comparatively narrow intervening ribs which fit the bore of the matrix so t'hat'th ingot may lie in'the bore of the matrix with its axis concentric With that of the matrix, and so that under the radial pressure of a mandrel the metal is forced'into contact with the walls of the bore of the matrix.

20. A metal ingot having acylindrical.

part adapted to fit the bore of a cylindrical matrix and having longitudinal grooves proceeding from the opposite end of the "ingot and fading away into the cylindrical part, the ribs ,between the grooves fitting the bore of the matrix, so that the ingot may lie in the bore of the matrix with its axis concentric with that of the matrix.

Signed at 22 Carlton House Terrace, Westminister, London, England, this'sixth dayof June, 1917. v

EOEEET ABBOTT HADFIELD. ALEXANDER GEORGE MCKENZIE nor.

Witnesses 7. JOHN HAROLD HALLATT,

WILLIAM CRoss. 

